• 한국군사과학기술학회지
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• 제27권2호
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• pp.127-139
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• 2024

This paper discusses a gravity compensation technique designed to reduce wavefront error caused by gravity during the assembly and alignment of satellite multi-band optical sensor. For this study, the wavefront error caused by gravity was analyzed for the opto-mechanical structure of multi-band optical sensor. Wavefront error, an indicator of optical performance, was computed by using the displacements of optics calculated through structural analysis and optical sensitivity calculated through optical analysis. Since the calculated wavefront error caused by gravity exceeded the allocated budget, the gravity compensation technique was required. This compensation technique reduces wavefront error effectively by applying the compensation load to the appropriate position of the housing tube. This method successfully meets the wavefront error budget for all bands. In the future, a gravity compensation equipment applying this technique will be manufactured and used for assembly and alignment of multi-band optical sensor.

• 한국기계가공학회지
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• 제7권4호
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• pp.17-23
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• 2008

Development of die technology for holder and barrel dies is necessary according to minimization of lens assembly, image sensor, and connectors. In these cases, there are two technical problems arising from die design. One is determination of knock-out pin location in die set. Minimization of lens assembly size make it difficult to obtain ejecting space. The other is whether or not high-precision die technology is possible to reduce torque variation when holer and barrel products is assembled. In this study, multi-cavity die set was developed taking advantage of gear-driven ejecting method. In the developed technology, die manufacturing technology was guaranteed with a high-precision level.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2006년도 춘계학술대회 논문집
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• pp.607-608
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• 2006

This article deals the development of Agile and Intelligent Manufacturing System(AIM) for the assembly automation of a tiny ultrasonic actuator used in camera phones and PDAs. The system consists of multi-vision modules, end-effectors, a standard base frame, dispensers, jigs and modular manipulators. Subsystems are a vision system, a force control system and a virtual reality system. Experimental results show that the assembly process for the small components in the various IT applications can be realized by the AIM system.

• 한국정밀공학회지
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• 제17권8호
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• pp.140-150
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• 2000

In this paper module of a product is determined by the characteristics of a product itself and process. To analyze the characteristics of the product information on subassemblies and parts can be obtained by analyzing the existing product. Based on the analysis of characteristics of product structure and function determination rules of a module degree could be proposed for assembly and disassembly process and product structure and function. By applying these rules of a module, module of a product is classified into full half and non-module depending on the module degree of a product. As a result of module degree analysis simpler assembly process and reduced structural interference can be realized. For the product function simpler updated and multi function can be also achieved.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회A
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• pp.1585-1589
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• 2007

The HANARO, a 30 MW multi-purpose research reactor in Korea, will be equipped with a neutron guide system, in order to transport cold neutrons from the neutron source to the neutron scattering instruments in the neutron guide hall near the reactor building. The neutron guide system of HANARO consists of the in-pile plug assembly with in-pile guides, the primary shutter with in-shutter guides, the neutron guides in the guide shielding room with dedicated secondary shutters, and the neutron guides connected to the instruments in the neutron guide hall. The functions of the in-pile plug assembly are to shield the reactor environment from a nuclear radiation and to support the neutron guides and maintain them precisely oriented. The primary shutter is a mechanical device to be installed just after the in-pile plug assembly, which stops neutron flux on demand. This paper describes the mechanical design of the in-pile plug assembly and the primary shutter for the neutron guide system at HANARO. The design of the guide shielding assembly for the primary shutter and the neutron guides is also presented.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회A
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• pp.30-34
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• 2008

The transfer assembly (or transfer printing) technique is a promising method for fabricating multi-scale structures on various substrates including semiconductors and polymers, and has been applied to fabrication of flexible devices with superior performance to conventional organic flexible devices. The mechanical behaviors of the structures fabricated by the transfer assembly is a very important information for design and reliability evaluation purpose, but the measurement of the behaviors is difficult since their critical-dimensions are very tiny. In this study, Au films with nano-scale thickness were fabricated on a silicon substrate and their mechanical properties were measured using micro-tensile test. The Au films on the silicon substrate were then transferred to a PDMS substrate using the transfer assembly technique. Self-assembled monolayer (SAM) with a thiol group was used to enhance the transfer of Au films, and the mechanical behaviors were characterized using wrinkle-based test. The test results from micro-tensile and wrinkle-based test are compared to each other, and their implication to the transfer assembly technique is discussed.

• Industrial Engineering and Management Systems
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• 제8권3호
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• pp.181-193
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• 2009

This paper presents a framework for controlling mobile multiple robots connected by communication networks. This framework provides novel methods to control coordinated systems using mobile agents. The combination of the mobile agent and mobile multiple robots opens a new horizon of efficient use of mobile robot resources. Instead of physical movement of multiple robots, mobile software agents can migrate from one robot to another so that they can minimize energy consumption in aggregation. The imaginary application is making "carts," such as found in large airports, intelligent. Travelers pick up carts at designated points but leave them arbitrary places. It is a considerable task to re-collect them. It is, therefore, desirable that intelligent carts (intelligent robots) draw themselves together automatically. Simple implementation may be making each cart has a designated assembly point, and when they are free, automatically return to those points. It is easy to implement, but some carts have to travel very long way back to their own assembly point, even though it is located close to some other assembly points. It consumes too much unnecessary energy so that the carts have to have expensive batteries. In order to ameliorate the situation, we employ mobile software agents to locate robots scattered in a field, e.g. an airport, and make them autonomously determine their moving behaviors by using a clustering algorithm based on the Ant Colony Optimization (ACO). ACO is the swarm intelligence-based methods, and a multi-agent system that exploit artificial stigmergy for the solution of combinatorial optimization problems. Preliminary experiments have provided a favorable result. In this paper, we focus on the implementation of the controlling mechanism of the multi-robots using the mobile agents.

• 한국음향학회지
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• 제20권8호
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• pp.19-23
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• 2001

고속 저전력의 DSP (Programmable Digital Signal Processor)가 개발됨에 따라 이동통신 분야에서 시스템 및 단말기 등이 DSP를 사용하여 구현되고 있다. 본 논문에서는 DSP를 사용한 AMR (Adaptive Multi-rate) 음성부호화기의 멀티 채널 실시간 구현에 관하여 논한다. AMR 음성부호화 알고리즘을 250 MHz로 동작하는 32비트 정수형 DSP 칩인 TMS320C6202를 사용하여 구현하였다. 실시간 동작을 위하여 cross compile, 선형 어셈블리 최적화, TMS320C62xx 어셈블리 최적화 작업을 수행하였다. AMR 음성부호화기에 음성 데이터 입출력 기능 및 외부 CPU와의 통신기능을 포함하였다. DSP EVM 보드를 사용하여 AMR 음성부호화기를 개발하였고, ETRI에서 개발중인 비동기 IMT-2000 시스템 상에서 동작 및 기능을 검증하였다.

• 마이크로전자및패키징학회지
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• 제19권4호
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• pp.45-50
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• 2012

A family of multi-die DRAM packages was developed that incorporate the full functionality of an SODIMM into a single package. Using a common ball assignment analogous to the edge connector of an SODIMM, a broad range of memory types and assembly structures are supported in this new package. In particular DDR3U, LPDDR3 and DDR4RS are all supported. The center-bonded DRAM use face-down wirebond assembly, while the peripherybonded LPDDR3 use the face-up configuration. Flip chip assembly as well as TSV stacked memory is also supported in this new technology. For the center-bonded devices (DDR3, DDR4 and LPDDR3 ${\times}16$ die) and for the face up wirebonded ${\times}32$ LPDDR3 devices, a simple manufacturing flow is used: all die are placed on the strip in a single machine insertion and are sourced from a single wafer. Wirebonding is also a single insertion operation: all die on a strip are wirebonded at the same time. Because the locations of the power signals is unchanged for these different types of memories, a single consolidated set of test hardware can be used for testing and burn-in for all three memory types.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2004년도 추계학술대회 논문집
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• pp.760-763
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• 2004

This work presents OLP system made independently in HSD for sub-assembly welding robot system set already and assembly welding robot system developed lately on the low speed diesel engines. This paper focuses on the DB module and the job creation based upon it. Also, It contains the welding history DB that saves the information of jobs executed after welding.